This invention relates generally to an electric power amplifier and, more particularly, to a switching power amplifier which minimizes switching transients normally associated with switching amplifiers.
Heretofore, switching amplifiers have been utilized which replace conventional linear amplifiers. In addition some amplifiers have used metal oxide silicon field effect transistor switches to replace bipolar transistors in the circuit design.
These designs have proven to be less than completely satisfactory in that the amplifier circuits thereof have a low throughput efficiency, require complex support circuitry to allow the amplifier to track the input signal and require output switching devices which can handle the large amounts of power they waste. High current capacity switching devices are necessary since earlier designs require the output switching elements to be able to absorb high switching transient currents.
The power is wasted each time the switches are cycled because earlier designs will turn on a switching device while the opposing device is conducting through its uncontrolled flyback diode. This diode will require some amount of time to recover and until it releases there will be an effective short-circuit across the supply. The energy that is drawn from the supply will be dissipated in one or both of the switching devices, thus a high speed switching amplifier will require fast recovery diodes and switching devices that can dissipate the power that is wasted.
Accordingly, it is desirable to provide a high-speed flyback modulated switching amplifier which eliminates the foregoing difficulties.